Bill of Quantities Checklist: 10 Checks Before You Submit

A bill of quantities checklist is a fixed review routine that an estimator runs before submitting quantities, so that errors are caught by method rather than by luck. The ten checks below cover units, revisions, scale, duplicates, missing items, typical details, contradictions, element groups, traceability and a final sanity review. Running the same list on every project is what makes it effective.

Why does a bill of quantities need a checklist?

A bill of quantities needs a checklist because its costliest errors are silent: a duplicated element, a missing pile group or an assumed thickness all produce a total that looks perfectly plausible. A checklist forces the reviewer to look for each failure type explicitly instead of relying on whether the total "feels right".

Totals are a poor control. Two opposite errors can cancel each other out, and a single omission can hide inside a large figure. A structured review also creates a record: when a client or consultant later questions a quantity, the estimator can show which checks were made and what was resolved. The three most common silent errors are explained in the hidden assumptions behind bill of quantities errors.

What are the 10 checks to run before submitting a bill of quantities?

The ten pre-submission checks for a bill of quantities move from the basis of measurement, through the drawings themselves, to the final figures. Run them in order, and record the outcome of each.

1. Units match the contract. Confirm every item is measured in the unit the contract or method of measurement requires: typically rebar and structural steel by weight in tonnes, concrete by volume in m³. Check that kilograms have been converted to tonnes consistently.
2. Every sheet is the latest revision. Compare the revision of each drawing used against the current drawing register. A quantity taken from a superseded sheet is wrong even if the measurement was perfect.
3. Scale is verified on every sheet. Check a known dimension on each sheet against its stated scale, especially for PDF drawings. A sheet read at the wrong scale distorts every length and, even more, every area.
4. No element is counted twice. Elements often appear on a plan, a section and a detail. Make sure each one is counted once, from one agreed source.
5. No element is missing. Walk through the structure from foundations to roof: piles, pile caps, footings, ground beams, pedestals, columns, walls, slabs, beams, stairs and any secondary steel.
6. Typical details are applied everywhere they occur. A typical detail is drawn once but applies to many locations. Confirm it has been multiplied by the correct number of occurrences.
7. Contradictions are resolved, not assumed. Where a plan, section or note disagree, record the conflict and the answer from the designer instead of choosing silently.
8. Element groups are reviewed separately. Review subtotals by group (for example, foundations, frame, slabs) rather than only the grand total, so that a missing group stands out.
9. Sample lines are traced back to the drawing. Choose several lines at random and confirm the element, dimension and sheet behind each one.
10. A final sanity review is done by a second person. A colleague who did not prepare the quantities should read the summary against the drawings with fresh eyes.

How do you spot duplicates across drawing sheets?

Duplicates across drawing sheets are spotted by assigning every element a single source sheet and checking that elements visible elsewhere are marked as already counted. The risk is highest where the same element is shown in plan, in section and in an enlarged detail.

Illustrative example: a 10 m concrete beam measuring 0.3 × 0.6 m appears both on the floor plan and on a longitudinal section. Its volume is 0.3 × 0.6 × 10 = 1.8 m³. If both drawings are measured, the bill shows 3.6 m³ for one beam. For a steel IPE 300 beam of the same length, the duplicate adds 10 × 42.2 = 422 kg. Repeated across a floor, these small duplicates become a significant overstatement that makes the tender less competitive.

How do you find items that are missing entirely?

Items that are missing entirely are found by checking the takeoff against a structural walk-through rather than against the drawings that happen to be open. Elements shown on separate sheets, such as piles, pile caps, pedestals and reinforcement cages, are the most likely to fall out.

Illustrative example: a foundation sheet shows 10 piles of Ø60 cm, each 12 m long. A pile of Ø60 cm has a cross-section of 0.283 m², so each pile holds 0.283 × 12 = 3.396 m³ of concrete, roughly 3.4 m³, and the group holds about 34 m³. If the pile sheet was never included in the takeoff, those 34 m³ and the matching reinforcement cages disappear from the bill without any warning. The volume formulas for each element type are covered in how to calculate concrete quantities.

How do you check that typical details have been applied?

Typical details are checked by counting how many locations each detail applies to and confirming the takeoff includes that count, not just the single instance drawn. Typical details often carry trimming bars, edge reinforcement, connection plates and similar items that never appear on the main plans.

Illustrative example: a typical detail requires 4 additional Ø12 bars, each 2 m long, around every slab opening, and the plans show 20 openings. That is 20 × 4 × 2 = 160 m of Ø12 bar. At 0.888 kg/m, the detail adds about 142 kg of rebar. In steelwork, the same logic applies to typical connection plates, as shown in how to calculate structural steel quantities.

Which checks matter most for steel, rebar and concrete?

The checks that matter most differ by trade, because each trade hides its errors in a different place. The table below summarises where to look first.

How does software change the review of a bill of quantities?

Software changes the review of a bill of quantities by moving the effort from arithmetic to verification: the reviewer checks how the result was reached rather than recalculating it. That only works if every line can be traced back to the drawing and if unclear information was raised rather than assumed.

Quantap was designed around both points. Every line in the report can be checked back against the drawing, and when something is unclear, missing or contradictory, Quantap asks through Quick Check instead of guessing, then updates the quantities with the answers. The results are for professional review and do not replace professional engineering judgement, so the checklist above still applies in full. More questions about the review process are answered in the FAQ.

Summary

A bill of quantities checklist turns review from intuition into method. The ten checks cover units, revisions, scale, duplicates, missing elements, typical details, contradictions, element groups, traceability and a second reviewer. Illustrative examples show how a duplicated beam, a forgotten pile group or an unapplied typical detail can each shift the figures noticeably while leaving the total looking plausible. Running the same list on every project, whether quantities were measured by hand or by software, is the most reliable protection before submission.